Patent GB-520225-A (GB)
Title: Improvements in or relating to machines for harvesting potatoes and other root crops
IPC: A01D17/00
Filed: 1938-07-16
Abstract: 520,225. Digging root crops. HUTCHISON, T. M., PAGE, W. S., GIRLING, A., HUTCHISON, T., and SCOTTISH AGRICULTURAL INDUSTRIES. Ltd. July 16, 1938, Nos. 14598/38 and 23667/39. [Class 6 (iii)] [Also in Group II] An elevator or riddling device, suitable for use in separating soil from. potatoes, comprises a. grid-like surface made up of a number of transverse rows of .spaced rockers, the rockers of adjacent rows being placed end to end, and a number of parallel transverserows of moving fingers carried on an endless chain &c., the ends of the fingers passing along the slots formed by the spaces between adjacent rockers. In the construction shown in Figs. 1, 2 and 3 (14598/38), the machine is connected by a draw-bar 3 to a tractor, the power shaft of which is coupled through universal joints 6 to a shaft 5. The frame of the machine is adjustable by means of a lever 8 having a rack engaged by pinions 10. A transversely-reciprocating cutter 45 is adapted to cut the haulm as the machine advances, and the haulm is cleared away by a rotating brush 42. The share 41 is a continuation of a horizontal plate 20 from which the material loosened by the share is conveyed away by an elevator 11. The floor of the elevator, is in the form of a grid composed of rows of spaced rockers 21. In the spaces between the rockers pass fingers 13 mounted on transverse bars 14 the ends of which are guided between endless rails 15, 16. The outermost fingers engage with driving-pins carried by sprocket-chains 17 so that all the fingers have parallel movement. The rockers 21 are oscillated through the medium of a crank fitted on the shaft carrying the sprocket 19. Below the upper end of the elevator floor is a riddle 27 with two sieves 28, 29. The riddle is given a jigging motion. The sieve 28 rejects roots and pieces of haulm which are discharged from a spout 30. Potatoes and stones fall on the sieve 29 and are transferred to a belt conveyer 33. The conveyer is tilted near its forward end so that the potatoes are delivered to an elevator 34 while the stones are discharged over the end of the conveyer. The elevator has a grid-like floor through which pass fingers 37 driven by sprocket-chains on wheels 39, 40. The potatoes are thus transferred to a waggon. In a modification shown in. Figs.  2 and 3 (23667/39) the material dug by the share 114 is collected by a rotary lifter comprising six arms 112 each having prongs 113 arranged to point always in the same direction as the lifter rotates. The prongs lift the material on to a grid 115 and into the path of an elevator 116. The elevator comprises rows of fingers 117 on transverse bars 118 which are attached to endless chains 119. The floor of the elevator consists of rows of spaced rockers 122 which are oscillated by cranks on the shaft of sprocket 121. The material after leaving the rockers falls on a travelling riddle of endless belts arranged to form a coarse screen above a finer screen. Haulm is removed by the coarse screen and a diagonal plate 136 extends across the lower screen to transfer the material to a moving band 137. The band transfers the potatoes to a discharge conveyer 163. The arms 112 describe approximately frustro-conical surfaces of revolution, and the prongs remain on the same side of the arms so that there is little tendency for material to be carried round and round by the prongs.